What causes the AC indicator light to flash in a Mitsubishi Pajero when the AC is turned on?
1 Answers
AC compressor clutch not engaging. Fault description: The engine ECU has received the air conditioning request signal from the AC ECU (since the AC fan operates when the AC is turned on). Referring to the circuit diagram, measurements show that when the AC is on, the engine ECU can control the grounding of the fan relay, but there is no control signal output for the AC compressor relay. Further testing of the wiring shows no grounding short circuits or open circuits; the wiring is normal. Additional relevant information is as follows: Notes: To further pinpoint the fault, use a diagnostic tool to read the data stream in the engine system. When the AC is turned on after starting the engine, the air conditioning request signal in the data stream is ON, and the air conditioning relay control is ON. After turning off the AC, the air conditioning request signal in the data stream is OFF, and the air conditioning relay control is OFF, indicating that the engine ECU has received the signal from the AC ECU. At this point, the fault point is clear—an issue with the air conditioning control panel. Check the low-pressure switch, high-pressure switch, transition to the air conditioning (blue section on the control panel), and possible issues with fuses and relays.
